Light filter



P. F. EARLY LIGHT FILTER June 6, 1950 Original Filed Oct. 16, 1943 JIE. 3

JIE. Z

INVENTOQ PHUL E EflELY BY ATTOQN EY Patented June 6, 1950 LIGHT FILTER Paul F. Early, Dayton, Ohio, assignor to Standard- Thomscn Corporation, a corporation of Dela- Ware Original application October 16, 1943, Serial No'.

506,482. Divided and thisapplication December 15, 1945, Serial No. 635,375

9 Claims. (Cl. 22.40-46.59)

This invention relates to a light filter and is designed primarily for use with alight projecting device when it is desired to subdue the brilliancy of the projected light. The present application is a division of my application filed October 16. 1943, serial No. 506,482, on which Patent No. 2,404,476, issued July 23, 1946.

one object of the invention is to provide alight filter, or screen, which can be quickly and easily attached to or removed from the body of a light projecting device.

A further object of the invention is to provide a filter with. attaching elements which have firm locking engagement with the body of the device, and with means for positively releasing said elements when the filter is to be removed.

A turther object of the invention is to provide such a filter which can be inserted in the end portion 01 a tubular body and when so inserted will constitute a continuation of the body, and will be attractive in appearance and will not be liable to displacement through accident or in.- advertcnce.

A further object of the invention is to providesuch a filter which is of a simple and inexpensive construction.

other objects of the invention may appear as the filter is described in detail.

In the accompanying drawings, Fig. '1 is a side view partly in section and partly in elevation of a light projecting device equipped with my improvide filter; Fig. 2 is an end elevation of the light projecting device and filter of Fig. 1; Fig. 3 is a transverse section taken on the line 3-3 of Fig. l and: looking in the direction of the arrows; and Fig 4 is a detail view of aportioni of one of the attaching devices.

In these drawings I have illustrated one embodiment of my invention and have shown the same as applied to a light projecting device of the type commonly called a, cocltpit'l'amp and designed primarily for use in military aircraft, where ease of operation and positive reliability are essential. However, it is tov be understood that the filter may take various forms and may be used with light projecting devices of variouslcinds without. departing from the spirit of the invention.

The light projecting device here shown by way of illustration comprises a tubular body inoluding' a rear portion 5, in which a lamp 6 is' supported, and. a front portion. 1 adapted to support a lens-1 8 and which is adjustable toward and from the rear portion, as shown and described in the above mentioned application. The front portion 5 of the body projects forwardly a short distance beyond the lens and is preferably of an internal diameter slightly greater than the diameter of the lens, thus enabling the filter to be inserted therein without obstructing the light from the lens. This forward portion of the body is pro vided. adjacent its open front endwith an internal shoulder, preferably a bead 9 extending entirely about the opening.

The filter comprises; a holder l0 which is adapted to be inserted in the open front end of the body and is preferably annular in form. As here shown, the holder has an inner portion ll of an external diameter slightly less than the internal diameter of the end portion of the body, and. an outer portion 12 of an external diameter approximating the external diameter of the end portion of the body. This outer portion is spaced from the inner end of the holder such a distance that it will contact with the end of the body when said inner end has been fully inserted in the latter, and thus positively limit the inward move ment of the holder. The filtering element I3 is supported in the holder at a suitable distance from the inner end thereof and is here shown as a circular disk having its peripheral edge portion seated in a groove HI in the holder. The filtering element may be of any suitable translucent ma terial, such'as glass or a suitable plastic, and may be of any desired color, usually red.

Yieldable attaching elements l5 are secured to the inner portion of the holder and extend for-- wardly between the same and the body. These attaching devices are here shown as resilient fingers the inner ends of which are bent about and rigidly secured to the inner end of the holder and the outer ends'of which extend beyond the front end of the body. Preferably the inner end of each finger is provided with outwardly extending parts I511 adapted to be inserted through an opening in the holder and to have their ends [5b bent laterally into contact with the holder (Fig.- 4). Each attaching element is provided between its ends with a part adapted to have retaining on gagement with a fixed part on the body; As here shown, each finger is bent to form therein a recess Is to receive the bead 9 on the body andis held in firm but yieldable' engagement with the bead by the resiliency of the finger. The inner portion of each finger slopes from its inner end to the recess It, so that the insertion of the holder in the body will depress the finger as it moves over the bead and the recessed portion of the finger will embrace the bead when it is brought into line therewith.

The enlarged outer portion of the holder is provided with radial sockets H, which constitute guideways, and with openings I-B through which, the fingers I5 may extend into the inner ends of the respective guideways. Plungers, or push buttons, I!) are slidably mounted in the guideways and are operatively connected with the respective fingers, as by screws 20. Thus the push buttons are held normally in their outer positions and may be pressed inwardly to move the fingers out of retaining engagement with the bead. Preferably the holder is connected with the body by a flexible connection or chain 2| to prevent its loss when not in use.

To attach the filter to the light projecting device it is only necessary to insert the inner end thereof in the open end of the bod and exert thereon sufiicient pressure to move the attaching fingers into retaining engagement with the bead. The bead being continuous the filter may be so inserted with the attaching elements in any positions about the axis of the body. When the filter is to be removed the push buttons are actuated to disengage the fingers from the bead and the filter is withdrawn by grasping the outer portion thereof and pulling it out of the body. Preferably two attaching devices are provided and these ar arranged on opposite sides of the holder so that they may be simultaneously actuated by the thumb and finger of the hand which grasps the. holder. The outer dimensions of the filter are such that when in place in the body it constitutes an extension of the latter and imparts to the projecting device as a whole a harmonious and pleasing appearance.

While I have shown and described one embodiment of my invention I wish it to b understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters- Patent is:

1. In a light projecting device comprising a tubular body having an open front end, means for supporting a lamp in said body and a lens supported in spaced relation to the open end thereof, a filter including a tubular holder having an inner portion to extend into said open end of said body and an outer portion to project beyond said body, a filtering element supported by said holder, attaching devices carried by said holder and extending into the open nd of said body, said body having within the same parts cooperating with said attaching devices to retain said holder therein, and means operable from the exterior of said device to disengage said attaching devices from said body.

2. In a light projecting device comprising a tubular body having an open front end, means V for supporting a lamp in said body and a lens supported in spaced relation to the open end thereof, a filter including a tubular holder having an inner portion to extend into said open end of said body and an outer portion to project beyond said body, a filtering element supported by said holder, resilient members secured to the inner portion of said holder on opposite sides of the latter extending outwardly therefrom, said members and said body having cooperating parts to retain said holder in the open end of said body, andactuating members movably mounted in the outer portion of said holder and connected with the respective resilient members to disengage the latter from said body.

3. In a light projecting device, a tubular body open at its front end and having within the same and adjacent said open end an internal circumferential bead, a lens supported in the rear of said bead, a filter including an annular holder having an inner portion to extend into the open end of said body and an outer portion to project beyond said body, a filtering element supported in said holder, and resilient fingers secured to the inner portion of said holder and extending outwardly therefrom, said fingers having parts to yieldably engage said bead and retain said holder in the open end of said body.

4. In a light projecting device, a tubular body open at its front end and having within the same and adjacent said open end an internal circumferential bead, a lens supported in the rear of said bead, a filter including an annular holder having an inner portion to extend into the open end of said body and an outer portion to project beyond said body, a filtering element supported in said holder, resilient fingers secured to the inner portion of said holder and extending outwardly therefrom, said fingers having parts to yieldably engage said bead and retain said holder in the open end of said body, and actuating members movably supported on the outer portion of said holder and operable to move said resilient members out of engagement with said bead.

5. In combination with a light projecting device including a tubular member having an open end portion, a filter comprising an annular holder having a part adapted to extend into the open end of said tubular member, an attaching element secured to the inner end portion of said part of said holder, extending outwardly beyond said part exteriorly of said holder and having a yieldable part adapted to have retaining engagement with said tubular member, and a filtering element carried by said holder.

6. In combination with a light projecting device including a tubular member having an open end portion, a filter comprising an annular holder having a part adapted to extend into the open end of said tubular member, an attaching element secured to said part of said holder, extending outwardly from its point of connection therewith and having a yieldable part adapted to have retaining engagement with said tubular member, an actuating device supported by said holder outwardly beyond that portion of the latter which extends into said tubular member and arranged to disengage said retaining part of said attaching element from said tubular member, and a filtering element carried by said holder.

'7. A filter for a light projecting device comprising an annular holder having end portions of difierent diameters, a resilient finger secured to the smaller end portion of said holder extending externally thereof toward the larger end portion of said holder and having between its ends a retaining part, an actuating member supported by the larger end portion of said holder and connected with said finger to move said retaining part thereof to an inoperative position, and a filtering element carried by said holder.

8. A filter for a light projecting device comprising an annular holder having an inner end portion and an outer end portion of greater diameter than said inner portion, said outer portion having a guideway, a resilient attaching element secured to said inner portion and extending outwardly to a point adjacent said guideway, said resilient element having a retaining part spaced from the outer end thereof, an actuating member movably supported in said guideway and operatively connected with the outer portion of said resilient element, and a filtering element supported in said annular holder.

9. A filter for a light projecting device comprising an annular holder having an inner end portion and an outer end portion of greater diameter than said inner portion, said outer portion having a substantially radial guideway, resilient fingers secured to said inner portion extending into the respective guideways and each having between its ends a retaining part, actuating members slidable in the respective guideways and connected with said fingers, and a filtering ele ment in said holder.

PAUL F. EARLY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 231,702 DeGrange Aug. 31, 1880 831,803 Schindewolf Sept. 25, 1906 1,214,363 Peters Jan. 30, 1917 1,933,896 Dupuis et al. Nov. 7, 1933 FOREIGN PATENTS Number Country Date 113,554 England Feb. 28, 1918 498,677 France Oct. 25, 1919 

